But, then, perhaps no future president will ask for such congressional
involvement in the gravest decision government makes -- going to war. Why would
future presidents ask, if the present administration successfully asserts its
current doctrine? It is that whenever the nation is at war, the other two
branches of government have a radically diminished pertinence to governance, and
the president determines what that pertinence shall be. This monarchical
doctrine emerges from the administration's stance that warrant-less surveillance
by the National Security Agency targeting American citizens on American soil is
a legal exercise of the president's inherent powers as commander in chief, even
though it violates the clear language of the 1978 Foreign Intelligence
Surveillance Act, which was written to regulate wartime surveillance.

Will seems to think the wiretapping a reasonable approach, and thinks Congress should authorize it, but its very reasonableness or even necessity does not justify executive circumvention of the Constitution:

Besides, terrorism is not the only new danger of this era. Another is the
administration's argument that because the president is commander in chief, he
is the "sole organ for the nation in foreign affairs." That non sequitur is
refuted by the Constitution's plain language, which empowers Congress to ratify
treaties, declare war, fund and regulate military forces, and make laws
"necessary and proper" for the execution of all presidential powers . Those
powers do not include deciding that a law -- FISA, for example -- is somehow
exempted from the presidential duty to "take care that the laws be faithfully
executed."